The present invention relates to a portable viscometer which allows field viscosity measurements to be accurately taken of various liquids.
Viscosity, a property of fluid bodies resulting from molecular attraction which makes them offer resistance to flow, is an important indicia of the grade and quality of many liquid substances. For instance, in the road construction industry asphalt cements, liquid asphalts and emulsions are used in production of asphalt concrete for use in construction of roads and parking lots. The quality and grade of the asphalt cements, liquid asphalt or asphalt emulsions used determines in a large part the characteristics of the finished paved surface. Another reason being, during the refining process of asphalt products samples must be taken periodically and tested in the laboratory. This invention may be used as an intermediate quality control step. For this reason during road construction, it has become more prevalent to determine some of the characteristics of the asphalt cements, etc. used. Viscosity measurement is an accurate determinant, but it is mostly made in a laboratory using samples obtained in the field. This viscosity data can then be correlated to important characteristics of the finished paved surface, such as compression strength and resistance to deformation under stress and heat. Samples are usually taken from each truck or tank car load of asphalt used, and are therefore representative of the road section fabricated with that particular truck or tank car load.
In the paint industry viscosity is, also, an important indicia of the quality and grade of the paint. Laboratory viscosity tests are often performed on paint samples, but it would be advantageous to have "in the plant" viscosity measurements.
In one type of test, the viscosity of a liquid, at a certain temperature, can be determined by timing the flow of a known amount of the liquid under a standard head through a standard orifice. In the past, however, accurate viscosity measurement of this type had to be made in laboratories because there was no means for accurately performing the tests in the field. This procedure can cause difficulties because the laboratory tests often cannot be performed until long after the road section is completeed or long after the paint has been mixed and packaged for sale.